Crepidula cachimilla is a species of sea snail, a marine gastropod mollusk in the family Calyptraeidae, the slipper snails or slipper limpets, cup-and-saucer snails, and Chinese hat snails.
The species was described based on specimens from southwestern Atlantic Ocean in , Argentina (type locality).
The maximum recorded shell length is 52.2 mm. The species is morphologically distinct from other species of Crepidula. These anatomical differences include a projecting apex and the absence of a periostracum. It also has a thicker columellar muscle than other mature Atlantic species of Crepidula.
Minimum recorded depth is 10 m. Maximum recorded depth is 20 m. It attaches to hard substrata.